High-voltage switch cabinet temperature monitoring system and monitoring method
Technical Field
The invention relates to the technical field of power system state monitoring, in particular to a high-voltage switch cabinet temperature monitoring system and a monitoring method.
Background
The high-voltage switch cabinet is not only a working device for switching on and off normal loads, but also the most important protection device in power equipment, and not only needs to switch on and off normal working current, but also bears the task of switching on and off fault current. As a core device in an electric power system, safe and stable operation of a high-voltage switch cabinet is very important.
After long-term operation, the surface and the interior of the high-voltage switch cabinet, especially the contact position, may cause the resistance value to increase due to poor contact, mechanical wear, pollution, partial discharge and the like, thereby causing a rapid increase in heat and finally causing a safety accident.
If the temperature change of monitoring cubical switchboard that can be accurate, in time discover the trouble, overhaul before the trouble spreads, just can be by a maximum extent reduce the operation risk of cubical switchboard, guarantee equipment and personal safety.
The existing temperature monitoring and alarming system and method generally adopt a temperature threshold value method, namely, the current temperature is compared with a system set threshold value, and if the current temperature exceeds the system set threshold value, an alarm is given. This method has the following drawbacks: the threshold value is set to be too low, the system is easy to report by mistake, and faults can not occur for many days after alarming, so that the alarming reliability and the reference significance are reduced; the threshold value is set to be too high, an alarm is given when the fault is approached, and sufficient maintenance time is not reserved to cause electrical fault.
Therefore, the threshold value is set without referring to specific running conditions such as load current, working environment and the like, so that the judgment and alarm are inaccurate, the temperature online monitoring system loses practical significance, and the user investment is invalid.
Disclosure of Invention
The invention aims to provide a temperature monitoring system and a temperature monitoring method for a high-voltage switch cabinet, which aim to solve the problems of temperature defect missing report and false report generated by the factors of single threshold judgment mode, no consideration of the change of the threshold in different temperature difference states, lack of threshold correction and the like of the traditional temperature monitoring alarm system and alarm method and realize the aim of improving the accuracy and the reliability of the monitoring system and the monitoring method.
The invention is realized by the following technical scheme:
the utility model provides a high tension switchgear temperature monitoring system, is including installing temperature sensor and the running condition collection system on the cubical switchboard, temperature sensor, running condition collection system are connected with the temperature analysis system electricity, the temperature analysis system includes:
the temperature testing module is used for receiving temperature data from the temperature sensor, forming a temperature actual measurement curve based on the temperature data, and sending the temperature actual measurement curve to the data processing module and the temperature difference analysis module;
the temperature prediction module is used for receiving temperature data from the temperature sensor and operating condition data of the operating condition acquisition device, forming a temperature prediction curve based on the temperature data and the operating condition data, and sending the temperature prediction curve to the data processing module;
the operation condition testing module is used for receiving the operation condition data from the operation condition acquisition device and sending the operation condition data to the data processing module and the temperature difference analysis module;
the data processing module is used for receiving the temperature actual measurement curve and the temperature prediction curve, comparing the slope and/or the numerical value of the temperature actual measurement curve and the temperature prediction curve, and sending a temperature difference analysis signal to the temperature difference analysis module if the slope and/or the numerical value exceed the corresponding threshold;
and the temperature difference analysis module is used for receiving the temperature actual measurement curve and the operation condition data, performing multi-state temperature difference analysis based on the temperature actual measurement curve and the operation condition data after receiving the temperature difference analysis signal, and feeding back a judgment result to the data processing module.
In the high-voltage switch cabinet temperature monitoring system provided by the invention, the data acquisition device of the system comprises a temperature sensor and an operation condition acquisition device, which are the same as those in the prior art. The temperature sensor is used for collecting the temperature of a key joint contact in the high-voltage switch cabinet, and comprises a weak connector which is most prone to failure in the high-voltage switch cabinet such as a moving contact, a fixed contact, a busbar and a main transformer connector, or the temperature of the surface of the high-voltage switch cabinet such as the top, the front panel or the back panel. The operation condition acquisition device comprises but is not limited to a load current sensor, a humidity sensor and an air flow sensor, wherein the load current sensor is used for acquiring load current of incoming lines and/or outgoing lines of the switch cabinet, the humidity sensor is used for acquiring environmental humidity data, and the air flow sensor is used for acquiring environmental air flow data.
The temperature sensor and the operation condition acquisition device are electrically connected with a temperature analysis system of the system so as to send the acquired data to the temperature analysis system for analysis and monitoring.
Different from the prior art, the temperature analysis system comprises a temperature testing module, a temperature prediction module, an operating condition testing module, a data processing module and a temperature difference analysis module. The temperature testing module collects temperature data tested by the temperature sensor, forms a temperature actual measurement curve and transmits the temperature actual measurement curve to the data processing module and the temperature difference analysis module; the temperature prediction module predicts a temperature model by adopting the existing grey prediction method based on the temperature data and the operation condition data to form a temperature prediction curve and transmits the temperature prediction curve to the data processing module; the operation condition testing module receives operation environment parameters such as load current, humidity, air flow and the like of an inlet wire and an outlet wire of the switch cabinet and transmits operation data to the data processing module and the temperature difference analysis module; the data processing module receives a temperature prediction curve of the temperature prediction module and a temperature measured curve of the temperature testing module, compares the slope and the value of the prediction curve and the measured curve, and sends a temperature difference analysis signal to the temperature analysis module if the slope exceeds a slope threshold and/or the temperature value exceeds a temperature threshold; the temperature difference analysis module receives a temperature difference analysis signal of the data processing module, and performs multi-state temperature difference analysis based on initial data of the temperature difference analysis, which is based on data of the temperature difference test module and data of the operating condition test module, wherein the multi-state temperature difference analysis comprises but is not limited to inter-phase temperature difference analysis, historical temperature difference analysis, environmental temperature difference analysis and interval temperature difference analysis. And if the temperature difference in at least one temperature difference state exceeds the corresponding threshold value, an alarm signal is fed back to the data processing module and the alarm module.
In the multi-state temperature difference analysis, the inter-phase temperature difference analysis is A, B, C three-phase temperature difference in the comparison high-voltage switch cabinet, an inter-phase difference threshold value is preset aiming at a system according to the obvious correlation of the three-phase temperature difference, whether the comparison actual measurement difference value is within the threshold value or not is judged, and if not, an alarm is given. The historical temperature difference analysis is to compare the test temperature with historical temperature information of the same period and the same position, and if the temperature information exceeds a preset difference threshold value of the system, an alarm is given. And analyzing and comparing the difference value between the test data and the ambient temperature through ambient temperature difference analysis, and giving an alarm if the difference value is greater than a preset threshold value. And (4) comparing the test data with similar operating conditions including the temperature difference values at the same interval, such as load current, environment temperature and humidity, air convection and the like, by interval temperature difference analysis, and alarming if the temperature difference values are greater than a preset threshold value.
Through the arrangement, the high-voltage switch cabinet temperature monitoring system abandons a judgment mode of pre-storing a fixed temperature value and a fixed threshold value in the prior art, firstly, a temperature prediction model is established to analyze the temperature change trend, and the slope and the numerical value of a temperature prediction curve and a temperature actual measurement curve are compared to obtain an abnormal temperature point, so that the predicted temperature reference point is attached to the actual operation environment, and the error caused by the environment change is greatly reduced; secondly, after the slope and the numerical value are abnormal, the data processing module controls the temperature analysis module to carry out multi-dimensional and multi-state analysis on the slope and the numerical value, so that on one hand, the judgment by adopting a single temperature difference threshold value is avoided, the accuracy and the reliability of the monitoring system are effectively improved, and the situations of missing report and false report of the temperature defect are prevented; on the other hand, various temperature difference threshold values can be further analyzed according to abnormal temperature values, accurate temperature alarm is achieved, the fault type can be conveniently and rapidly determined by workers, and maintenance efficiency is improved.
Further, the temperature analysis system further comprises an alarm module, when the temperature difference in at least one temperature difference state exceeds a threshold value, the temperature difference analysis module sends an alarm signal to the alarm module, and the alarm module receives the alarm signal and then gives an alarm for temperature defects.
Further, the temperature defect alarm comprises a common alarm signal and an important alarm signal, the common alarm signal identifies a single temperature difference state in which data exceeds the limit, and the important alarm signal identifies a plurality of temperature difference states in which data exceeds the limit. The alarm module realizes temperature defect alarm, and the alarm includes ordinary warning and important warning, and wherein ordinary warning sign what kind of difference in temperature data transfinites, and what kind of difference in temperature data of important warning sign transfinites, if a plurality of differences in temperature exceed and predetermine poor threshold value, then carry out important temperature and report an emergency and ask for help or increased vigilance, show that the cubical switchboard is probably defect to have appeared.
As a preferred embodiment of the present invention, the temperature analysis system is connected to a big data cloud, and the big data cloud is configured to receive a temperature measured curve, a temperature predicted curve, a temperature defect alarm, and operation condition data of the temperature analysis system, and optimize a model for establishing the temperature predicted curve and/or optimize a threshold of each temperature difference state in the multi-state temperature difference analysis based on the temperature measured curve, the temperature predicted curve, the temperature defect alarm, and the operation condition data.
The big data cloud receives data such as temperature test data, temperature alarm data and defect processing feedback reports of the temperature analysis system, and adjusts and optimizes various thresholds of the temperature analysis system according to the running condition, so that continuous evolutionary learning of the system is realized. And the big data optimization function performs data optimization on the optimal time sequence of the temperature model in the system, the interphase temperature difference threshold value of multi-state analysis, the historical temperature difference threshold value, the environmental temperature difference threshold value and the interval temperature difference threshold value.
And if the prediction model is not consistent with the actual model, namely the slope threshold and the numerical threshold are exceeded, but the multi-state temperature difference analysis shows that the temperature distribution is normal, the temperature prediction model is marked to be inaccurate, and the optimal time sequence of the temperature model is optimized. The method of optimizing the optimal time series of the temperature model is to update the time series by replacing different time series if a prediction curve formed by the new time series is more matched with the actual curve.
Further, if the predicted time sequence does not conform to the reality, including exceeding a slope threshold and a numerical threshold, but the temperature difference threshold is always within the setting range, but the temperature defect exists actually, namely when the temperature defect is missed, the temperature difference threshold is updated, the temperature difference threshold is reduced, and after the system deduces that the reduced temperature difference threshold cannot be missed, the big data cloud sends the updated threshold to the temperature analysis system. If the predicted time sequence is consistent with the actual time sequence, but the temperature difference threshold value always exceeds the set range, namely, the temperature difference threshold value is reported by mistake, the temperature difference threshold value is updated, the temperature difference threshold value is increased, and after the temperature difference threshold value increased by deduction of the system is not reported by mistake, the big data cloud end sends the updated threshold value to the temperature analysis system.
The large data optimization system does not update the threshold value according to single or few false reports and missing reports, but updates the threshold value after a large amount of data is accumulated, so that misoperation of the system caused by a few abnormal data is prevented, and all data updates are released after being jointly approved by clients and background research and development.
By setting the big data cloud end, the system precision can be continuously optimized, and the model precision and the temperature difference analysis precision can be optimized by updating the optimal time sequence of the temperature model and the multi-state analysis temperature difference threshold value.
In some embodiments, the system has the same type of switch cabinet defect diagnosis function, abnormal heating states of the switch cabinets under similar operation conditions are evaluated by adopting the Mahalanobis distance, deep analysis is carried out according to the manufacturer and the model of the switch cabinet, the performance difference between the model and the brand and the consistency defect of the same brand and model are found, and a product quality defect report is given. The mahalanobis distance method is adopted to carry out deep analysis and abnormal evaluation on the temperature information of different high-voltage switch cabinets which are located in the same distribution room, different distribution rooms, different transformer substations or power plants and operate under similar conditions, so that the switch cabinets with heating defects can be effectively checked out, and the mahalanobis distance method can be used for finding the defects of 'family type' products.
The invention also provides a high-voltage switch cabinet temperature monitoring method, which adopts any one of the monitoring systems for monitoring and comprises the following steps:
the method comprises the following steps: the temperature sensor collects temperature data and sends the temperature data to the temperature testing module and the temperature predicting module; the operation condition acquisition device acquires operation condition data and sends the operation condition data to the data processing module and the temperature difference analysis module;
step two: the temperature testing module receives temperature data from the temperature sensor, forms a temperature actual measurement curve based on the temperature data, and sends the temperature actual measurement curve to the data processing module and the temperature difference analysis module;
and acquiring temperature data of all parts of the high-voltage switch cabinet by means of a front-end temperature sensor, and generating a temperature actual measurement curve.
Step three: the temperature prediction module receives temperature data from a temperature sensor and operation condition data of the operation condition acquisition device, forms a temperature prediction curve based on the temperature data and the operation condition data, and sends the temperature prediction curve to the data processing module;
based on the temperature data and the monitoring data of the running environment such as load current, environment humidity, ambient air flow and the like, the temperature prediction module establishes a temperature prediction model according to a built-in temperature model algorithm, and the time interval of the temperature prediction model is 1 hour.
Step four: the data processing module receives and compares the slopes and/or values of the temperature actual measurement curve and the temperature prediction curve, sends a temperature difference analysis signal to the temperature difference analysis module if the slopes and/or values exceed corresponding thresholds, and continues to monitor, receive and compare the slopes and/or values of the temperature actual measurement curve and the temperature prediction curve if the slopes and/or values do not exceed corresponding thresholds;
and comparing the slope and the value of the actual temperature and the temperature prediction model, if the slope and the value difference threshold value are exceeded, performing multi-state temperature difference analysis, and if the slope and the value difference threshold value are not exceeded, continuously monitoring the temperature.
Step five: the temperature analysis module receives the temperature difference analysis signal, performs multi-state temperature difference analysis based on the temperature actual measurement curve and the operation condition data, judges whether the temperature difference in each temperature difference state exceeds a threshold value in the corresponding temperature difference state, and feeds back the judgment result to the data processing module.
And performing multi-state temperature difference analysis, analyzing various temperature difference data, and covering various temperature defects.
Further, the method also comprises the following steps: through multi-state temperature difference analysis, when the temperature difference in at least one temperature difference state exceeds a corresponding threshold value, the temperature difference analysis module sends an alarm signal to the alarm module, and the alarm module receives the alarm signal and then gives an alarm for temperature defects. If a certain temperature difference exceeds a preset difference threshold value, a common temperature alarm is carried out, and the defect of the temperature difference is displayed. And if the temperature differences exceed the preset difference threshold value, important temperature alarm is carried out, and the fact that the switch cabinet is possibly defective is indicated.
Further, the method also comprises the following steps: the temperature analysis system is connected with a big data cloud end, and after receiving a temperature actual measurement curve, a temperature prediction curve, a temperature defect alarm and operation condition data of the temperature analysis system, the big data cloud end optimizes the model used for establishing the temperature prediction curve and/or optimizes the threshold value of each temperature difference state in the multi-state temperature difference analysis based on the temperature actual measurement curve, the temperature prediction curve, the temperature defect alarm and the operation condition data.
As another preferred embodiment of the present invention, a conventional gray prediction algorithm is modified. Specifically, in the third step, when the temperature prediction curve is established, firstly, the operation state monitoring data of the high-voltage switch cabinet is acquired by the front-end temperature and operation environment sensor and is used as the basic data of the model establishment, and then the method comprises the following steps:
s1: smoothing the temperature data and the operating condition data;
and carrying out data smoothing on the temperature test data, and improving the model prediction precision. Preferably, when the temperature prediction model is established, a five-point three-time smoothing method is used for carrying out data smoothing, and the end points and the middle points are respectively smoothed to smooth the time series trend. Since the high-voltage switch cabinet temperature contact has local random fluctuation, and since each value of the time sequence is possible to be used as the initial value of the prediction. The randomness of the data sequence can be reduced in a limited way by carrying out smoothing processing on the endpoint value and the interval, and the prediction precision is improved. The data smoothing process adopts a five-point three-time smoothing method to respectively smooth the break points and the intermediate points, so as to smooth the time sequence trend, reduce the random fluctuation of the original prediction data sequence and improve the accuracy of the temperature prediction model.
S2: selecting a time series length;
the optimal time sequence length is selected, the optimal time sequence is selected by calculating the mean square error of different time sequence lengths, the initial recommended time sequence of the system is 1 hour, and the cloud optimization of the big data of the system can realize the optimization and the updating of the time sequence according to the actual operation result.
S3: generating a gray sequence;
s4: establishing and solving a differential equation to obtain a primary accumulation sum sequence of a prediction result;
and establishing a differential equation based on the first-order accumulation sum result, and solving the differential equation to obtain a first-order accumulation sum sequence of the prediction result. And reconstructing a background value by utilizing integral, optimizing the background value by an integral method after the gray index sequence is accumulated for one time, and reducing the error of the background value by utilizing discrete interval serialization of a continuous function and solving the curved edge area of an interval by the integral.
S5: accumulating, reducing and reducing to obtain a temperature predicted value;
s6: and correcting the predicted value through residual error checking.
The monitoring method not only introduces the traditional grey prediction algorithm, but also optimizes the algorithm. On one hand, the data smoothing treatment adopts a five-point three-time smoothing method to respectively smooth the break points and the intermediate points, so as to smooth the time sequence trend, reduce the random fluctuation of the original prediction data sequence and improve the accuracy of the temperature prediction model; on the other hand, the system reconstructs a background value by utilizing integral, optimizes the background value by an integral method after accumulating the gray index sequence for one time, utilizes a continuous function to disperse interval serialization, solves the curved edge area of the interval by integral, reduces the error of the background value, and thereby improves the model precision.
Compared with the prior art, the invention has the following advantages and beneficial effects:
1. according to the method, a judgment mode of pre-storing a fixed temperature value and a fixed threshold value in the prior art is abandoned, a temperature change trend is analyzed by establishing a temperature prediction model, and the slope and the numerical value of a temperature prediction curve and a temperature actual measurement curve are compared to obtain an abnormal temperature point, so that a predicted temperature reference point is attached to an actual operation environment, and errors caused by environment changes are greatly reduced; secondly, after the slope and the numerical value are abnormal, the data processing module controls the temperature analysis module to carry out multi-dimensional and multi-state analysis on the slope and the numerical value, so that on one hand, the judgment by adopting a single temperature difference threshold value is avoided, the accuracy and the reliability of the monitoring system are effectively improved, and the situations of missing report and false report of the temperature defect are prevented; on the other hand, various temperature difference thresholds can be further analyzed according to the abnormal temperature values, so that accurate temperature alarm is realized, the fault type can be conveniently and quickly determined by workers, and the maintenance efficiency is improved;
2. according to the method, the big data cloud is arranged, the system precision can be continuously optimized, and the model precision and the temperature difference analysis precision are optimized by updating the optimal time sequence of the temperature model and the multi-state analysis temperature difference threshold value; the large data optimization system does not update the threshold value according to single or few false reports and missing reports, but updates the threshold value after a large amount of data is accumulated, so that misoperation of the system caused by a few abnormal data is prevented, and all data updates are released after being jointly approved by clients and background research and development;
3. according to the method, a temperature prediction model is optimized on the basis of a traditional grey prediction algorithm, on one hand, a five-point three-time smoothing method is adopted for data smoothing, the breakpoints and the intermediate points are smoothed respectively, the time sequence trend is smoothed, the random fluctuation of an original prediction data sequence is reduced, and the accuracy of the temperature prediction model is improved; on the other hand, the system reconstructs a background value by utilizing integral, optimizes the background value by an integral method after accumulating the gray index sequence for one time, utilizes a continuous function to disperse interval serialization, solves the curved edge area of the interval by integral, reduces the error of the background value, and improves the model precision;
4. the alarm comprises a common alarm and an important alarm, wherein the common alarm identifies which temperature difference data exceeds the limit, the important alarm identifies which temperature difference data exceeds the limit, and if a plurality of temperature differences exceed a preset difference threshold, the important alarm gives an important temperature alarm to indicate that the switch cabinet is possibly defective;
5. according to the invention, the abnormal heating state of the switch cabinet under the similar running condition is evaluated by adopting the Mahalanobis distance, deep analysis is carried out according to the manufacturer and the model of the switch cabinet, the performance difference between the model and the brand and the consistency defect of the same brand and model are found, and a product quality defect report is given.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a schematic diagram of a temperature monitoring system in an embodiment of the present invention;
FIG. 2 is a block flow diagram of a method for temperature monitoring in an embodiment of the present invention;
FIG. 3 is a block diagram of a process for creating a temperature prediction curve according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.
In the description of the present invention, it is to be understood that the terms "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "high", "low", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and therefore, are not to be construed as limiting the scope of the present invention.
The term "connected" used herein may be either directly connected or indirectly connected via other components without being particularly described.
Example 1:
as shown in fig. 1, the high-voltage switch cabinet temperature monitoring system comprises a temperature sensor and an operation condition acquisition device which are installed on a switch cabinet, wherein the temperature sensor and the operation condition acquisition device are electrically connected with a temperature analysis system, and the temperature analysis system comprises:
the temperature testing module is used for receiving temperature data from the temperature sensor, forming a temperature actual measurement curve based on the temperature data, and sending the temperature actual measurement curve to the data processing module and the temperature difference analysis module;
the temperature prediction module is used for receiving temperature data from the temperature sensor and operating condition data of the operating condition acquisition device, forming a temperature prediction curve based on the temperature data and the operating condition data, and sending the temperature prediction curve to the data processing module;
the operation condition testing module is used for receiving the operation condition data from the operation condition acquisition device and sending the operation condition data to the data processing module and the temperature difference analysis module;
the data processing module is used for receiving the temperature actual measurement curve and the temperature prediction curve, comparing the slope and/or the numerical value of the temperature actual measurement curve and the temperature prediction curve, and sending a temperature difference analysis signal to the temperature difference analysis module if the slope and/or the numerical value exceed the corresponding threshold;
and the temperature difference analysis module is used for receiving the temperature actual measurement curve and the operation condition data, performing multi-state temperature difference analysis based on the temperature actual measurement curve and the operation condition data after receiving the temperature difference analysis signal, and feeding back a judgment result to the data processing module.
In some embodiments, the temperature analysis system further comprises an alarm module, when the temperature difference in at least one temperature difference state exceeds a threshold value, the temperature difference analysis module sends an alarm signal to the alarm module, and the alarm module receives the alarm signal and then gives an alarm for temperature defects.
In some embodiments, the temperature defect warning includes a general warning signal identifying a single temperature difference state in which the data is overrun and an important warning signal identifying a plurality of temperature difference states in which the data is overrun.
In some embodiments, the operation condition acquisition device includes a load current sensor, a humidity sensor and an air flow sensor, wherein the load current sensor is used for acquiring load current of incoming lines and/or outgoing lines of the switch cabinet, the humidity sensor is used for acquiring environmental humidity data, the air flow sensor is used for acquiring environmental air flow data, and the operation condition data includes the load current, the environmental humidity data and the environmental air flow data.
In some embodiments, the multi-state temperature difference analysis includes inter-phase temperature difference analysis, historical temperature difference analysis, environmental temperature difference analysis, and interval temperature difference analysis.
And analyzing and comparing the interphase temperature difference, comparing A, B, C three-phase temperature differences in the high-voltage switch cabinet, presetting an interphase difference threshold value aiming at the system according to the obvious correlation of the three-phase temperature differences, comparing whether the actually measured difference is within the threshold value, and if not, giving an alarm. In some embodiments, the temperature of contact A is Ta, the temperature of contact B is Tb, the temperature of contact C is Tc, the AB interphase threshold is [ T1, T2], the AC interphase threshold is [ T3, T4], and a fault in contact A is alarmed if [ Ta-Tb > T2 or Ta-Tb < T1] and [ Ta-Tc > T4 or Ta-Tc < T3 ]. The inter-phase threshold values are automatically matched in the interval range of different operating conditions and are simultaneously optimized by a system big data optimization system.
Historical temperature difference analysis is carried out to compare the test temperature with historical temperature information in the same period and the same position, and if the test temperature exceeds a preset difference threshold value of the system, an alarm is given. In some embodiments, the temperature dead center temperature designed by the historical temperature difference analysis further comprises interval temperature equalization, interval temperature difference, interval maximum temperature, interval minimum temperature and temperature equalization times, the interval value is the same as the time sequence of the temperature prediction model, the initial value is 1 hour, and the interval value changes along with the optimization of the time sequence of the temperature prediction model. In some embodiments, the temperature of the point A under test is T, the temperature of the historical contemporaneous and collocated point is T1, the historical temperature difference threshold of the system is T0, and if the absolute value of T-T1 is greater than T0, the fault of the point A is alarmed. The historical temperature difference threshold values are automatically matched in the interval range of different operating conditions and are optimized by a big data optimization system.
And comparing the difference between the test data and the ambient temperature by the ambient temperature difference, and alarming if the difference is greater than a preset threshold value. In some embodiments, the test temperature is T, the ambient temperature is T0, the preset ambient temperature difference threshold is T1, and if | T-T0| > T1, a fault is alarmed. The environmental temperature difference threshold T1 is different according to seasons, operating environment, switch cabinet models and the like, is automatically matched within the range of different operating conditions, and is optimized by a big data optimization system.
And comparing the test data with similar running conditions including the temperature difference values at the same interval of load current, environment temperature and humidity, air convection and the like by interval temperature difference, and alarming if the temperature difference values are larger than a preset threshold value. In some embodiments, the interval temperature difference identifies whether the interval is the interval of the same operation condition through the ID number of the front-end sensor, if the interval is the interval of the same operation condition, the same series ID number of the front-end sensor is configured, and the temperature data collected by all the same series ID numbers are regarded as the same interval. Such as: the testing temperature is T, the simultaneous data acquired by the sensors in the same ID series is T0, the preset interval temperature difference threshold is T1, and if the absolute value of T-T0 is greater than T1, a fault is alarmed. The interval temperature difference threshold data is optimized by a big data optimization system. The compartments may be the same or different electrical distribution rooms, or even different substations or power plants.
The multi-state temperature difference analysis effectively overcomes the defect that the temperature is judged by a single threshold value, and multi-angle, multi-environment and multi-state temperature difference analysis is realized. Meanwhile, the multi-state temperature difference analysis introduces the operation condition data of the switch cabinet, including load current, environment temperature and humidity, air convection and the like, and the temperature difference threshold values in the interval ranges of different operation conditions can be automatically matched, so that the multi-dimensional temperature analysis is realized. In some embodiments, the system divides the operating conditions into a plurality of grades respectively, wherein the grades comprise load current, environment temperature and humidity and air convection, the three operating condition factors correspond to different temperature difference thresholds under different combinations, the system selects different thresholds to measure and calculate the temperature difference according to the current operating state instead of unifying the thresholds into one threshold, and the accuracy, pertinence and reliability of temperature defect judgment are improved.
Example 2:
on the basis of embodiment 1, the temperature analysis system is connected with a big data cloud end, the big data cloud end is used for receiving a temperature actual measurement curve, a temperature prediction curve, a temperature defect alarm and operation condition data of the temperature analysis system, and optimizing a model used for establishing the temperature prediction curve and/or optimizing the threshold value of each temperature difference state in multi-state temperature difference analysis based on the temperature actual measurement curve, the temperature prediction curve, the temperature defect alarm and the operation condition data.
And if the prediction model is not consistent with the actual model, namely the slope threshold and the numerical threshold are exceeded, but the multi-state temperature difference analysis shows that the temperature distribution is normal, the temperature prediction model is marked to be inaccurate, and the optimal time sequence of the temperature model is optimized. The method of optimizing the optimal time series of the temperature model is to update the time series by replacing different time series if a prediction curve formed by the new time series is more matched with the actual curve.
If the predicted time sequence is not consistent with the actual time sequence, the predicted time sequence comprises a slope threshold and a numerical value threshold, but the temperature difference threshold is always within the setting range, but the temperature defect exists actually, namely, the temperature defect is reported in a missing mode, the temperature difference threshold is updated, the temperature difference threshold is reduced, and after the temperature difference threshold reduced by the system is deduced to be not reported in a missing mode, the big data cloud sends the updated threshold to the temperature analysis system. If the predicted time sequence is consistent with the actual time sequence, but the temperature difference threshold value always exceeds the set range, namely, the temperature difference threshold value is reported by mistake, the temperature difference threshold value is updated, the temperature difference threshold value is increased, and after the temperature difference threshold value increased by deduction of the system is not reported by mistake, the big data cloud end sends the updated threshold value to the temperature analysis system.
The big data cloud receives data such as temperature test data, temperature alarm data and defect processing feedback reports of the temperature analysis system, and various thresholds of the temperature analysis system are adjusted and optimized according to the running condition, so that continuous evolutionary learning of the system is realized. And the big data optimization function performs data optimization on the optimal time sequence of the temperature model in the system, the interphase temperature difference threshold value of multi-state analysis, the historical temperature difference threshold value, the environmental temperature difference threshold value and the interval temperature difference threshold value.
The large data optimization system does not update the threshold value according to single or few false reports and missing reports, but updates the threshold value after a large amount of data is accumulated, so that misoperation of the system caused by a few abnormal data is prevented, and all data updates are released after being jointly approved by clients and background research and development.
By setting the big data cloud end, the system precision can be continuously optimized, and the model precision and the temperature difference analysis precision can be optimized by updating the optimal time sequence of the temperature model and the multi-state analysis temperature difference threshold value.
Example 3:
on the basis of the embodiment, the system has the function of diagnosing the defects of the switch cabinets of the same type, the abnormal heating state of the switch cabinets under the similar running condition is evaluated by adopting the Mahalanobis distance, deep analysis is carried out according to the manufacturer and the model of the switch cabinets, the performance difference among the models and the consistency defects of the same model and the same brand are found, and a product quality defect report is given. The mahalanobis distance method is adopted to carry out deep analysis and abnormal evaluation on the temperature information of different high-voltage switch cabinets which are located in the same distribution room, different distribution rooms, different transformer substations or power plants and operate under similar conditions, so that the switch cabinets with heating defects can be effectively checked out, and the mahalanobis distance method can be used for finding the defects of 'family type' products.
Example 4:
as shown in fig. 2, the method for monitoring the temperature of the high-voltage switch cabinet adopts any one of the monitoring systems for monitoring, and the method comprises the following steps:
the method comprises the following steps: the temperature sensor collects temperature data and sends the temperature data to the temperature testing module and the temperature predicting module; the operation condition acquisition device acquires operation condition data and sends the operation condition data to the data processing module and the temperature difference analysis module;
step two: the temperature testing module receives temperature data from the temperature sensor, forms a temperature actual measurement curve based on the temperature data, and sends the temperature actual measurement curve to the data processing module and the temperature difference analysis module;
step three: the temperature prediction module receives temperature data from a temperature sensor and operation condition data of the operation condition acquisition device, forms a temperature prediction curve based on the temperature data and the operation condition data, and sends the temperature prediction curve to the data processing module;
step four: the data processing module receives and compares the slopes and/or values of the temperature actual measurement curve and the temperature prediction curve, sends a temperature difference analysis signal to the temperature difference analysis module if the slopes and/or values exceed corresponding thresholds, and continues to monitor, receive and compare the slopes and/or values of the temperature actual measurement curve and the temperature prediction curve if the slopes and/or values do not exceed corresponding thresholds;
step five: the temperature analysis module receives the temperature difference analysis signal, performs multi-state temperature difference analysis based on the temperature actual measurement curve and the operation condition data, judges whether the temperature difference in each temperature difference state exceeds a threshold value in the corresponding temperature difference state, and feeds back the judgment result to the data processing module.
In some embodiments, the method further comprises the following steps: through multi-state temperature difference analysis, when the temperature difference in at least one temperature difference state exceeds a corresponding threshold value, the temperature difference analysis module sends an alarm signal to the alarm module, and the alarm module receives the alarm signal and then gives an alarm for temperature defects.
In some embodiments, the method further comprises the following steps: the temperature analysis system is connected with a big data cloud end, and after receiving a temperature actual measurement curve, a temperature prediction curve, a temperature defect alarm and operation condition data of the temperature analysis system, the big data cloud end optimizes the model used for establishing the temperature prediction curve and/or optimizes the threshold value of each temperature difference state in the multi-state temperature difference analysis based on the temperature actual measurement curve, the temperature prediction curve, the temperature defect alarm and the operation condition data.
Example 3:
as shown in fig. 3, in the third step, based on embodiment 2, when the temperature prediction curve is established, firstly, the monitoring data of the operating state of the high voltage switchgear is obtained by using the front end temperature and the operating environment sensor as the basic data for model establishment, and then the method includes the following steps:
s1: smoothing the temperature data and the operating condition data;
and carrying out data smoothing on the temperature test data, and improving the model prediction precision. Preferably, when the temperature prediction model is established, a five-point three-time smoothing method is used for carrying out data smoothing, and the end points and the middle points are respectively smoothed to smooth the time series trend. Since the high-voltage switch cabinet temperature contact has local random fluctuation, and since each value of the time sequence is possible to be used as the initial value of the prediction. The randomness of the data sequence can be reduced in a limited way by carrying out smoothing processing on the endpoint value and the interval, and the prediction precision is improved. The data smoothing process adopts a five-point three-time smoothing method to respectively smooth the break points and the intermediate points, so as to smooth the time sequence trend, reduce the random fluctuation of the original prediction data sequence and improve the accuracy of the temperature prediction model.
S2: selecting a time series length;
the optimal time sequence length is selected, the optimal time sequence is selected by calculating the mean square error of different time sequence lengths, the initial recommended time sequence of the system is 1 hour, and the cloud optimization of the big data of the system can realize the optimization and the updating of the time sequence according to the actual operation result.
S3: generating a gray sequence;
s4: establishing and solving a differential equation to obtain a primary accumulation sum sequence of a prediction result;
and establishing a differential equation based on the first-order accumulation sum result, and solving the differential equation to obtain a first-order accumulation sum sequence of the prediction result. And reconstructing a background value by utilizing integral, optimizing the background value by an integral method after the gray index sequence is accumulated for one time, and reducing the error of the background value by utilizing discrete interval serialization of a continuous function and solving the curved edge area of an interval by the integral.
S5: accumulating, reducing and reducing to obtain a temperature predicted value;
s6: and correcting the predicted value through residual error checking.
The monitoring method not only introduces the traditional grey prediction algorithm, but also optimizes the algorithm. On one hand, the data smoothing treatment adopts a five-point three-time smoothing method to respectively smooth the break points and the intermediate points, so as to smooth the time sequence trend, reduce the random fluctuation of the original prediction data sequence and improve the accuracy of the temperature prediction model; on the other hand, the system reconstructs a background value by utilizing integral, optimizes the background value by an integral method after accumulating the gray index sequence for one time, utilizes a continuous function to disperse interval serialization, solves the curved edge area of the interval by integral, reduces the error of the background value, and thereby improves the model precision.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.